Beijing, China (CNN) -- The trial of four Rio Tinto employees charged with bribery and stealing commercial secrets ended in Shanghai Wednesday, but it was unclear when a verdict would be reached.

"I'm not sure when the verdict will come out," says Zhang Peihong, lawyer of Wang Yong, one of the defendants. He said his client admitted to some of the charges with qualifications.

"There is a dispute regarding the $9 million Wang Yong took," Zhang says. "The prosecutor said the amount is bribe, but our side argued that it's the price differential in the commodities transaction."

Charged in the case are Stern Hu, an Australian citizen of Chinese origin who was the general manager of Rio Tinto's Shanghai office. Hu has been in detention for nine months, along with Rio Tinto's three Chinese employees -- Liu Caikui, Ge Minqiang and Wang Yong. They are accused of taking bribes and stealing commercial secrets.

Rio Tinto, a British-Australian company, is one of the largest mining companies in the world. The case has raised fears of a government crackdown on foreign companies doing business in China.

The three-day trial was closed to foreign news organizations, hindering independent confirmation of developments. At the end of the first day of the trial on Monday, Zhai Jian -- the lawyer for another defendant -- said his client acknowledged receiving money, but said it was a gift or a loan -- not a bribe.

Australian consular officials were allowed in the Shanghai courtroom for the bribery phase of the case, but were barred from witnessing the theft portion.

Hu is accused of receiving two bribes: one for 1 million yuan ($146,490) and another for 5.3 million yuan ($790,000). The Australian Department of Foreign Affairs and Trade said he "made some admissions concerning these amounts," but did not elaborate.

The Chinese government initially accused the four of stealing state secrets when they were first detained, but the charges were reduced to theft of commercial secrets several months ago.

Hu and the others were detained in July. China says the four bribed executives from 16 of the nation's major steel mills to obtain industry information.

In China, obtaining commercial secrets carries a maximum penalty of seven years in prison.

Rio Tinto has called the allegations surprising and said it was not aware of any evidence.

The detentions took place about a month after Rio Tinto broke off an investment deal with China state-owned Chinalco, a resources company, that was worth more than $19 billion.

The deal with Chinalco was signed in February 2009 and was awaiting a review by Australia's foreign investment board.

The deal soured as opposition party members in Australia ratcheted up their disapproval, saying it would put Australian resources at strategic risk.

Others saw the deal as an alliance that would further link resource-rich Australia with the commodities-hungry Chinese market.